Abstract: Demand for network bandwidth is growing at unprecedented rates, placing growing demands on switching and transmission technologies. Wavelength division multiplexing will soon make it possible to combine hundreds of gigabit channels on a single fiber. This paper presents an architecture for Burst Switching Systems designed to switch data among WDM links, treating each link as a shared resource rather than just a collection of independent channels. The proposed network architecture separates burst level data and control, allowing major simplifications in the data path in order to facilitate all‐optical implementations. To handle short data bursts efficiently, the burst level control mechanisms…in burst switching systems must keep track of future resource availability when assigning arriving data bursts to channels or storage locations. The resulting Lookahead Resource Management problems raise new issues and require the invention of completely new types of high speed control mechanisms. This paper introduces these problems and describes approaches to burst level resource management that attempt to strike an appropriate balance between high speed operation and efficiency of resource usage.
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Abstract: Optical crossconnects are rapidly emerging as critical elements for provisioning and restoration in high‐capacity wavelength‐division‐multiplexed optical networks. High port count appears to be emerging as particularly important in this core‐network application, with 500‐port optical crossconnects (OXC’s) widely expected to be needed within about five years. This requirement severely strains current optical‐switching technologies. The emergence of this new application is, however, beginning to stimulate new device technologies. One of these is the free‐space micromachined optical switch (FS‐MOS). This approach combines the advantages of free‐space interconnection and monolithic integrated optics, thus offering the possibility of achieving high port‐count in a small, low‐cost…system with excellent optical quality. In this paper, we review the fundamental principles, fabrication, and performance of the FS‐MOS, and discuss both its port‐count scalability and its ability to incorporate advanced optical‐networking functionality within the switch fabric itself.
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Abstract: Terabit IP switch router is a key to the success of next generation Internet (NGI) with its backbone capacity supporting exponentially increasing traffic. The challenges in designing a terabit IP switch router include (1) a large capacity switch fabric providing high speed interconnection for a number of smaller capacity router modules, and (2) a fast arbitration scheme resolving output contention within stringent time constraint while achieving high throughput and low delay. In this paper, an input–output buffered switch architecture with a speedup of two is employed; our simulation results show that it can nearly achieve the theoretic bound in average…delay/throughput performance of an output buffered switch. We propose a 256\times 256 multicast optical interconnection network (OIN) based on advanced wavelength division multiplexing (WDM) technology as the switch fabric for terabit IP switch routers. Its component and interconnection complexity, and power budget are evaluated. A novel ping‐pong arbitration (PPA) scheme is used to solve the output contention in the OIN. The arbitration time of an N ‐input switch can be achieved in the order of \log_4\lceil N/2\rceil . For instance, with N=256 the arbitration can be completed in 11 gates delay, less than 5 ns using the current CMOS technology, showing that the PPA scheme can support multiple terabit/s switch capacity.
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Abstract: The increased data traffic experienced today and the projected increase in the data traffic in the future demand exploration of novel approaches to IP transport such as transport of IP traffic over optics. The bimodal nature of the IP traffic: short packets which are typical of transactional‐style flows and large packets or bursts which are encountered in the transport of large data blocks requires, design of routers that are capable of routing packets with variable lengths efficiently. In this paper, we discuss the design aspects of such all‐optical IP‐routers. The broadcast and select architecture is a prime candidate for…implementing optical IP routers. Construction of optical routers with buffering, wavelength conversion and multipath routing are considered. The merits and demerits of all these cases and the effect of buffer size, wavelength conversion and multiple‐path routing on the blocking probability and probability of packet loss are discussed.
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Abstract: To support bursty traffic on the Internet (and especially WWW) efficiently, optical burst switching (OBS) is proposed as a way to streamline both protocols and hardware in building the future generation Optical Internet. By leveraging the attractive properties of optical communications and at the same time, taking into account its limitations, OBS combines the best of optical circuit‐switching and packet/cell switching. In this paper, the general concept of OBS protocols and in particular, those based on Just‐Enough‐Time (JET), is described, along with the applicability of OBS protocols to IP over WDM. Specific issues such as the use of fiber delay‐lines…(FDLs) for accommodating processing delay and/or resolving conflicts are also discussed. In addition, the performance of JET‐based OBS protocols which use an offset time along with delayed reservation to achieve efficient utilization of both bandwidth and FDLs as well as to support priority‐based routing is evaluated.
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